An operating system used in making topographic surveys by percise measuring of distances by means of modulated microwaves. It must include two (2) or more SURVEYING INSTRUMENT, ELECTRONIC DISTANCE MEASURING, MICROWAVE units and may include equipment such as an electrotape unit with antenna and power supply, head set, battery cable, tripod, aneroid barometer, psychrometer, spare parts kits, and carrying case. Excludes radar sets.